Metal-Organic Frameworks as a Thermal Emitter for High-Performance Passive Radiative Cooling

Area of Science:

• Materials Science
• Nanotechnology
• Sustainable Energy

Background:

• Passive radiative cooling offers energy-free cooling solutions.
• Metal-organic frameworks (MOFs) are explored for their potential in radiative cooling applications.

Purpose of the Study:

• To investigate the optical properties of five MOFs for radiative cooling.
• To identify key factors influencing MOF performance in radiative cooling.

Main Methods:

• Spectroscopic analysis of MOFs (ZIF-67(Co), MOF-74(Ni), HKUST-1(Cu), MOF-801(Zr), UiO-66(Zr)).
• Evaluation of surface texture and porosity.
• Assessment of solar reflectance and mid-infrared emissivity.

Main Results:

• MOF cooling efficacy is linked to optical bandgaps and functional groups.
• UiO-66(Zr) exhibited high solar reflectance (91%) and mid-infrared emissivity (96.8%).
• A UiO-66(Zr) treated fabric achieved a 5°C temperature reduction and 26 W m⁻² cooling power.

Conclusions:

• MOFs, particularly UiO-66(Zr), show significant potential for passive radiative cooling.
• Findings pave the way for advanced, energy-efficient cooling technologies.
• Further research into chemical composition and structural characteristics is warranted.